Senior UI Developer

Senior UI Developer

At Trustonic, we make smartphones affordable for the many, enabling global access to devices and digital finance through the world's most secure smartphone locking technology. We partner with mobile carriers, retailers, and financiers across 30+ countries, powering device financing solutions that drive economic inclusion, profitability, and growth.

We pride ourselves on living by the Trustonic culture code, a blueprint for our journey that recognises that great working environments don't guarantee success, but bad ones almost always ensure failure.

Working here, you'll find a company that celebrates its diversity and is looking to do the right thing: for each other, the community and the planet. We believe in equal opportunities and take to heart the old African proverb 'If you only want to go fast, go alone. If you want to go far, go together'.

We work flexibly when and where we're at our best, but regardless of how you choose to work, we'll make sure you feel like one of the team.

If you would like to work in a fast-moving global technology company, with great ambition, then we'd love to hear from you!

Job Description

A bit about the role and what you'll do…

We're looking for a Senior UI Developer to take a leading role in building and evolving our operator web portal for a next-generation telecoms platform. You'll create intuitive, high-performance user interfaces that power device lifecycle management at scale—working at the intersection of frontend engineering, real-time data, and secure cloud integrations.

This is a high-impact role where you'll shape the user experience across a complex SaaS platform, collaborating closely with backend engineers and product teams to deliver seamless, scalable solutions. You'll play a key role in translating sophisticated platform capabilities into elegant, usable interfaces for customers.

Please note, this is a remote role with attendance required at our office in Winnersh from time to time.

Build Modern Web Experiences

Design, develop, and maintain a React 18-based operator portal, delivering responsive and intuitive user interfaces.

Create Reusable UI Components

Develop and maintain scalable component libraries using Ant Design, ensuring consistency and reusability across the platform.

Integrate with Cloud Services

Work with AWS AppSync GraphQL APIs and Cognito authentication flows to deliver secure, real-time user experiences.

Own State & Data Management

Implement efficient data-fetching and state management patterns (e.g., React Query, Zustand) for real-time device data.

Drive Frontend Performance

Optimise applications for speed and scalability through code-splitting, lazy loading, and caching strategies.

Collaborate Across Teams

Partner with backend engineers on API design and schema evolution, and contribute to UX and design discussions.

Ensure Quality & Reliability

Write robust unit and integration tests using Jest and React Testing Library, and contribute to code reviews and best practices.

Champion User Experience & Accessibility

Ensure applications meet high standards for responsiveness, cross-browser compatibility, and accessibility.

What we're looking for…

Experience & Expertise

• Strong commercial experience building production-grade React applications
• Proven experience working with GraphQL APIs (AppSync, Apollo, or similar)
• Experience implementing authentication flows (e.g., AWS Cognito, OAuth2/OIDC)
• Solid experience using TypeScript in a React codebase
• Familiarity with component libraries such as Ant Design, MUI, or similar

Technical Strength

• Deep understanding of React 18 (hooks, context, performance optimisation)
• Strong skills in TypeScript, including generics and scalable typing patterns
• Experience with modern tooling such as Vite or equivalent
• Knowledge of state management patterns (React Query, Zustand, or similar)
• Strong CSS/SCSS skills including responsive design (flexbox, grid)
• Experience with testing frameworks like Jest and React Testing Library

Nice to Have

• Experience with multi-tenant SaaS platforms at scale
• Familiarity with AWS services (AppSync, Cognito, S3, CloudFront)
• Understanding of web performance optimisation techniques
• Awareness of accessibility standards (WCAG)
• Experience working with design systems and UX best practices

Ways of Working

• Thrive in a fast-paced, collaborative engineering environment
• Strong attention to detail and passion for building high-quality user experiences
• Comfortable working across teams and contributing to shared solutions
• Proactive, organised, and able to take ownership of frontend systems
• Curious and motivated to continuously improve tools, patterns, and practices

Qualifications

• A degree in computer science, software engineering, or equivalent experience
• AWS certification is desirable but not essential

Additional Information

What we can provide you in return for your investment...

Competitive compensation

• A base salary that reflects your expertise and impact.
• Bonus scheme to share in our success.

Financial security & wellbeing

• Immediate participation in our pension scheme.
• Private medical insurance for you and your family from day one.
• Income protection and life insurance for peace of mind.

Flexibility & work-life balance

• Remote/hybrid working arrangements to support your lifestyle.
• An open holiday policy with no upper limit—take the time you need, when you need it.
• Support for volunteering and causes that matter to you.

Growth & development

• Opportunities for professional development and career progression.
• Exposure and interaction with global teams.

Inclusive, supportive culture

• A commitment to diversity, equity, and inclusion.
• A collaborative environment where your voice is valued and your wellbeing is prioritised.

Impact & purpose

• The chance to work on technology that drives global economic inclusion and makes a real difference in people's lives.

Trustonic is an equal opportunity employer. We do not discriminate on any grounds. We empower, engage, enable and value differences between people, including; different races, ethnicities, genders, ages, religions, disabilities and sexual orientations, with differences in education, backgrounds, skill sets, experiences and knowledge.